According to Professor William Pelham, who recently spoke to Britain’s Guardian Unlimited about research being conducted at the University of Buffalo, drugs such as Ritalin and Concerta may work well in the short term, but those benefits erode substantially over time and may even end up stunting a child’s growth.

That’s quite a different result than Pelham and his team found in the ‘90s, when they began monitoring about 600 children across the U.S. In 1999, the researchers suggested children diagnosed with ADHD would benefit more from medication than behavioral therapy. 

"I think we exaggerated the beneficial impact of medication in the first study,” Pelham told the Guardian Unlimited recently. “We had thought that children medicated longer would have better outcomes. That didn't happen to be the case.

"The children had a substantial decrease in their rate of growth, so they weren't growing as much as other kids in terms of both their height and their weight,” he added. “And the second was that there were no beneficial effects—none.

"In the short run [medication] will help the child behave better, in the long run it won't,” Pelham concluded. “And that information should be made very clear to parents." 

That doesn’t mean medication should be avoided entirely, however. Dr. Tim Kendall, of Britain’s Royal College of Psychiatrists, told the Guardian Unlimited, "I think the important thing is we have a comprehensive approach that doesn't focus on just one type of treatment."